And a few MMO game definitions:

WoW = World of Warcraft
CoH = City of Heroes
CoV = City of Villains
DAoC = Dark Age of Camelot
SWG = Star Wars Galaxies
AC = Asheron's Call


For LOTRO, the new expansion SoE = Shores of Evendim

A basic one:

Q = quest, any quest given to a player by an NPC listed in your quest log.

Chapter quests = for those who haven't yet reached that part of the Epic Quests - once you finish the Epic Quest Prologue you will find the Epic Quest continues as a series of Books, with each quest leg described as a Chapter.

LFF = looking for fellowship - use this when looking to start a pickup group fellowship to complete a quest.

Blind Invite = It is considered poor form to blindly invite someone to join a fellowship without an initial "tell" or chat or at least a broadcast on the LFF channel.

OOC = out of character. Use the OOC channel to chat out of character (i.e., real life).

RL = Real Life